Process for the manufacture of pearl essence



Patented July 5, 1932 JEAN PAISSEAU, OE PARIS, FRANCE PROCESS FOR THE MANUFACTURE OF PEARL ESSENCE No Drawing. Application filed March 18, 1929, Serial No. 348,147, and in Germany April 2, 1928.

Applicant has already specified in his United States Patent No. 1,576,454 filed in December 22, 1923, the preparation of pearl essence by the hot treatment of raw" material such as scales, bladders, fish skins, containing small and brilliant crystalloids, by the use of detersive agents, and in general of all substances adapted to produce foam, in an aqueous solution.

The process according to the present invention relates more particularly to the treatment of skins, bladders or the like which contain a large amount of pearl essence and also of fatty matter and conjunctive tissue. By reason of their density, such raw materials can only be decomposed with difliculty by the process specified in the aforesaid patent.

The applicant has observed that the said raw material is rapidly altered when in contact with the air, and that it undergoes a physical and chemical change by which it is made continually more resistant to the decomposition by the detersive agents, so that the resulting pearl essence has a rough consistency which precludes its use for the object intended.

F or this reason the invention relates to a process for the preservation of the raw material whereby the aforesaid change in density is obviated, and also to a process for obtaining pearl essence from such material, which latter process is based upon the same principle as the said preserving process.

According to the preferred method for the preservation of the raw material, the said material is immersed in a bath of water containing the proper proportion such as 1 to 5 per cent of an organic or inorganic acid which will gelatinize or at least swell and soften the tissue which serves as a backing for the minute and brilliant crystalloids, and this acid must be chosen among those which have little or no action upon the said crystals, such as formic, tartaric, acetic or other acids.

ervation a suflicient quantity of a neutral salt Y such as common salt, thus affording a solution whose molecular concentration is such that the conjunctive tissue will not be swelled and decomposed.

The said preserving process comprises by way of example the use of a bath containing 10 to 20 per cent of common salt or sodium chloride to which is added 1 to 5 per cent (or more) of an acid.

After the foregoing preserving process or step in my complete process of preparation of pearl essence, the surplus bath of acid or salt and acid is removed from the material and the latter is then subjected to further treatment for the separation of the crystalloids from the skins, bladders, etc. and for the cleaning of such crystalloids.

It has been observed that the substances which have thus been treated so as to preserve their properties for a long period, may be treated in an approved manner in a detersive bath containing the acids above mentioned, operating at 30-60 C. or above. It is necessary to use a detergent which acts (while maintaining all of its emulsifying properties) in a bath having an acid reaction.

According to the invention, saponine is the substance to be preferably employed for the purpose, although other substances may be used. By the use of the said detersive bath I am able to add at the proper moment a ferment of a proteolytic, or even a lipolytic nature, which will act in the acid bath. A bath having the following composition is preferably used with raw material such as bladders, skins or the like.

Water 1000 cubic centimeters consists in immersing the said parts, as soon V Acid 10 CUblC centuncters as they are removed from the fish, In an aque- Saponine 50 grams ous solution contannng l to 5 per cent of an Pepsin 5 grams organic acid which does not attack the This bath will sufiice for the treatment of 50100 grams or more of raw material, the amount of the said material varying with the quantity of pearl essence it contains.

The whole is raised to a suitable tern perature, and this should not exceed 45 C. when pepsin is added, but it may beheatedto amuch greater degree for instance up to 75 C., if the ferment is added only after a certain time. A suitable stirring is employed to subdivide the raw material to the maximum and to set free the brilliant crystals, and the latter can then be removed either by a natural settling or preferably by the centrifugal or other mechanical process.

In fact, after the above treatment, all the organic materials different from the crystalloids and constituting the framework or stroma of the raw materials treated are dissolved, so that the crystalloids are held in suspension in a kind of liquor more or less loaded with peptones. It results therefrom that the crystalloids can be easily separated under the influence of their own weight in the case of a spontaneous sedimentation or under the action of centrifugal force in the case of centrifugation. Pearl essence in the form of an aqueous paste is obtained through a decantation of the supernatant liquor, and it can be washed and purified by any known processes and subsequently held in suspension in any suitable liquid or incorporated with lacquers or varnishes.

The aforesaid examples are not of a limitative nature, and other methods may be employed. A ferment may thus be added after the action of the detersive agent, or

like operations and combinations may be used. The essential principle consists in the combined use of an acid which will dissolve the conjunctive tissue, with or without the use of a ferment or a detersive agent adapted to emulsify to the maximum degree, While separating them, the crystalloid substances which constitute the pearl essence.

I claim:

1. In a process for the treatment of the parts of fish which contain brilliant crystalloids by a dissociating bath, for the manufacture of essence of pearls, the operation which consists in immersing the said parts, as soon as they are removed from the fish, in a diluted aqueous solution of an organic acid having little or no action upon the said crys- 00 talloids and in maintaining them therein until they are treated by the dissociating bath.

2. In a process for the treatment of the parts of fish which contain brilliant crystal loids by a dissociating bath, for the manufactzi ture of essence of pearls, the operation which crystalloids, and in maintaining them therein until they are treated bythe dissociating bath.

3. In a process for the treatment of parts of fish containing brilliant crystalloids by a dissociating bath, for the manufacture of essence of pearls, the operation which consists in immersing and maintaining the said parts, as soon as they are removed from the fish, in a diluted aqueous solution of an organic acid having little or no action upon the said crystalloids and to which is added a neutral salt, such as chloride of sodium, in the propor tion of to per cent, and in maintaining them therein until they are treated by the dissociating bath.

4. In a process for the treatment of parts of fish containing brilliant crystalloids for the manufacture of pearl essence, the operations consisting in immersing and maintaining the said parts as soon as they are removed from the fish, in maintaining them in a diluted aqueous solution of an organic acid having little or no action upon the said crystalloids and to which is added a neutral salt, in removing from the said parts of fish the excess of the preserving liquid, in treating them at a suitable temperature in a dissolution bath constituted by the same acid solution without addition of salt, and in adding a detersive substance whose emulsifying properties are not counteracted by the acid of the said bath.

5. In a process for the treatment of parts of fish containing brilliant crystalloids, for the manufacture of pearl essence, the opera.- tions which consist in immersing and maintaining the said parts as soon as they are removed from the fish in a diluted aqueous solution of an organic acid having little or no action upon the said crystalloids and to which is added aneutral salt, in removing from the said parts of fish the excess of the preserving liquid and in treating them at a suitable temperature in a dissociation bath constituted by the same acid solution without addition of salt, and in adding to this solution a detersive substance whose emulsifying properties are not counteracted by the acid of the said bath and a proteolytic ferment, the action of which is combined with that of the detersive substance.

6. In a process for the treatment of parts of fish containing brilliant crystalloids, for the manufacture of pearl essence, the opera tions which consist in immersing and maintaining the said parts as soon as they are removed from the fish in a diluted aqueous solu tion of an organic acid having little or no action upon the said crystalloids and to which is added a neutral salt, in removing from the said parts of fish the excess of the preserving liquid and in treating them at a suitable temperature in a dissociation bath by the same acid solution without addition of salt, in add- 5 ing to this solution a detersive substance whose emulsifying properties are not counteracted by the acid of the said bath, and in removing the crystalloids from the said emulsion when they are completely freed from their organic gangue.

In testimony whereof I have hereunto affixed my signature.

JEAN PAISSEAU. 

